sustain (Bronshtein et al. 2006). It became apparent from studies that interaction

taking place between DNA and bacterial cells is greatly affected by ROS production

(Pramanik et al. 2012). Further, evidence corroborated the fact that ROS play an

intricate role in deciding the fate of the bacteria’s survival (Wang et al. 2017). This

might be attributed to the fact that ROS tend to escalate the gene expression levels of

oxidative proteins, which further governs the bacterial cell apoptosis mechanism

(Wu et al. 2011).

11.3.4 Non-oxidative Mechanisms

In the course of time, researchers have utilized varied state of the art analytical

techniques (viz., electron spin resonance (ESR), liquid chromatography-mass spec-

trometry (LC-MS)) in conjugation with imaging and spectroscopic analytical

techniques (viz., transmission electron microscopy (TEM) and Fourier transform

infrared (FT-IR)). They also utilized flat cultivation method in accordance with

proteomic tools to decipher the antibacterial activity of metallic (MgO) NPs on

E. coli (Leung et al. 2014; Wang et al. 2017). The experiment was conducted under

three different light conditions, viz., UV, natural, and dark conditions. The outcome

of the study clearly depicted that the incubation of NPs resulted in three vital

phenomena (Leung et al. 2014; Wang et al. 2017):

1. The energy dispersive X-ray (EDX) spectra clearly outnumbered the presence of

any MgO ion inside the periphery of the bacterial cell. Subsequently, TEM

analysis revealed the emergence of “pores” on the palisade region along with

disrupted and deformed cellular compartmental morphology.

2. A miniscule amount of generated ROS was detected by metallic NPs.

3. Negligible changes in the level of cell wall constituents (viz., lipopolysaccharide

(LPS) and phosphatidylethanolamine (PE)) were observed on tearing the bacteria

with the prepared NPs.

On the premises of these outrageous results, it can be summed up that MgO NP

treatments did not result in any sort of escalation in the lipid peroxidation or

ROS-associated protein production. However, these NPs resulted in a significant

decline in the levels of several cellular metabolomic processes, which had an innate

relationship with the essential regulatory processes of cell replication, lysis growth,

and division (Leung et al. 2014; Wang et al. 2017).

11.3.5 Mutation in Bacterial DNA

It came into being from varied studies that metallic ions produced because of

dissociation of NPs establish a facile interaction with the nucleic acid of microbes.

This interaction results in the termination of transcription and cell division cycle

(Dakal et al. 2016; Durán et al. 2016). This can be attributed to the fact that these

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